Ore-roasting apparatus.



010.050,039. A y PATENTED 0130.9, 1007. R. MGKNIGHT.

ORE ROASTING APPARATUS.

APPLIGATIoN FILED 0m10.190s.

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No. 850,039. PATENTRD APR. 9, 1907. R. MGKNIGHT.

ORE ROASTING APPARATUS.

APPLICATION FILED JULYe. 1903.

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y rrEn salaires ENEENYE Enron YEoEEE'r MeNNrenT, oErH Specification ofLetters Patent.

ELrnn/i, PENNSYLVANIA.

oss-acasrme appenni-Ue.

ltatented April 9, 1907.

Application filed July 6, 1903. Serial No. 164,342.

roasting apparatus embodying the hereindescribed lnvention. Fig. 2 is afull section on liney y, Fig. 1. Fig. 3 is a similar section on line zz, Fig'. 1.

This invention is an improvement in apparatus in the nature of aroasting-furnace for use more especially in carrying on processes forthe volatilization of precious metals from their ores and the'recovering of the metal values contained in the `fumes ofvolatilization-such, for example, as the process described in LettersPatent of the United States issued October 27, 1901, No. 685,691.

The main object of the invention is to provide such an apparatus inwhich balling or casking'of the ore being treated is obviated or-minimized, and also to completelyl expose the ore to the influenceofthe air in the furnace.

The invention consists in certain devices and combinations hereinafterdescribed and Referring to the accompanying drawings, one ortion of theapparatus consists of a fixe cylindrical structure 1, preferably linedon the inner side with tire-brick 2. Concentric with this structure is avertical shaft 3, that is journaled in suitable bearings and is adaptedto be rotated vfrom a source of power. series ofv obconic cones 4, ofsuitable material and preferably hollow, as shown.` As a convenientmeans for securing'these cones to the shaft 3, so as to be rotatabletherewith, I make said shaft square in cross-section, (exceptl the partwithin-the bearings) the holes of the cones being provided withcorrespondingopenings to receive the shaft, as seen. The said cones areslid upon the shaft, the lower end or hub of each resting upon the topof the next below, and the lowermost cone resting upon the bottom of thecylinder or, rather, inI this instance u on a box or bearing 5 Yof theshaft, whic bearing extends through the fire-brick lining of the bottomof the cylinder.

Fixedly mounted on this shaft is a Secured to and extending from theinner wall of the cylinder are a series of annuli 6,

preferably hollow, as shown, whose upper walls are inclined downwardlyand their lower walls or bottoms are substantially horizontal. The-p osein inclining downwardly the upper was of each of the annuli 6 isto'discharge the gravitating ore at the center of the next lower cone,and thus hold the ore uponthe cones for the greatest period of time. Thedimensions of'these annuli are,

as shown in Fig, 1, such as to leave an annu lar passage-way 7communicating between the bottom of each annulus and the top of the nextconebelow and between the sides of the annulus and the side of the cone.There is no annulus below the lowerrnost cone,

which cone is provided on opposite sides near its periphery with'Scrapers 8, two in the present instanceythat project into an annuartrough 9, that is cut away at one point to an opening 10, Fig. 3, thatisabove an outlet pipe or conduit 11 (hereinafter referred to)` Thebottom of the upper annulus is pro-A vided with numerous perforations15, and,

extending through the cylinder at a point above said bottom is a pipe 16for the escape of the fumes.

Having thus described my invention, I proceed to explain'the mode ofoperation thereof, as follows: The furnace having been started and theinterior of cylinder 1 becoming heated to a required temperature, theshaft 3 is driven at'a suitable speed, thus rotating the cones 4. Thepulverized ore orA IOC ore mixture is now fed into the hopper 14 anddescending upon the inclined to of the `upper oneof'the annuli is scrapeor agitated y the rotating Scrapers 13 and falls upon the top -of theupper one of the cones 4 adjacent to the shaft 3. The rotation of thecone p carries the ore outwardly in a thin layer by the centrifugalforce to the periphery of the cone -and it (the ore) then falls down theinoline of the second annulus 6, upon the sec- ICS , successively fromcone to cone on to the to. .of

the lowermost cone, from which it falls lnto a circular trough 9 and iscarried by the Scrapers 8 to the opening 10, whence it falls into thepipe 11 and' is delivered from the cylinderv 1. During the entire courseof the ore or ore mixture it is agitated and s read out and is at thesame time subjecte to a roasting process by the heat of thel furnace andthe air that enters the open end of the cylinder. In case the amount ofthis air be insufficient means may be employed for forcing a current ofair up through the appar ratus. The fumes formed in the process rise upthrough the lapertures 15 of the bottom o the upper ann us -and pass @ifby way of thei'umei elvtoasuitablecondenser. Usu ally it wil enecessaryor desirable to. use a suction device to aid in drawing off the fumes.

As is well known, in roasting ores containing gold and silver and alsocontaining metalloids-such as sulfur, phosphorus, &c.-`-a caking orhailing usually occurs, thus preventing perfect roasting andnecessitating regrinding of the balled ore. Silnilar difficulty occurswhen ores containing antimony, bismuth, dce., are subjected to atemperature of more than about 300 centigrade. Also ordinarily orescontaining the precious metals and lead or antimony cannot be thoroughlyroasted with sodium chlorid or other haloids`without balling. With myapparatus, hewever, the ore being agitated and thrown outwardly in asuccession of thin layers or bodies by the centrifugal force the heat orhot air entering the vertical vessel or cylinder 1 from the pipe 11 canreach every particle of the ore, and certainmetal or'metalloids thatwould cause caking or balling are eliminated-that is, the gradual travelor descent of the ore from a low to a high temperature volatilizes theexcess of metals and metalloids that cause the diiiiculty beforementioned.

Instead of having the lower end of cylinder 1 communicate with thefurnace, and

thus allowing the products of combustion to pass through the apparatus,I may sometimes use a furnace for generating superheated air, which isallowed to enter orl ings.

The Scrapers 13 maysometimes be dispensed with, as also. the Scrapers 8,and the trough 9 andother means substituted for conducting the ore to orcausing it to escape linto the pipe 11'.

. Having thus described my invention, I claim as new and desire tosecure by Letters Patent- 1. In an ore-roasting ap aratus, thecombination with ahollow cy inder, of a vertically-arranged rotatableshaft therein, a series of obconic cones mounted' on said shaft,

a corresponding series of annuli extendingv from the sides of' saidcylinder and arranged in the spaces between said cones tov forni a,

continuous passageway between the latter and said annuli, saidcylinderhaving at its l-us being perforatedv for collecting the fumes risingthrough the cylinder, and a pi e connected to' said topmost annulus foreading the collected fumes therefrom.

2. In an ore-roasting ap aratus, the combination with a hollow cy fnder,of a vertically-arranged. rotatable shaft therein, a series of obconiccones mounted on said shaft, a corresponding series of annuli'extendingfrom the sides of said cylinder and arranged in the spaces between saidcones to form -a continuous passage-way between the latter and saidannu-li, said cylinder having at its upper end an inlet for the ore andalso at its lower end an exit for the ore, a trough arranged below theedges of the lower cone for receiving the ore from the latter, Scraperscarried by said lower cone for discharging the ore from said trough intothe exit in the lower end of the cylinder, the topmost annulus beingperforated for collectingthe fumes rising through the cylinder, a ipelconnected tosaid topmost annulus for eading the collected fumestherefrom, and lScrapers connected to said shaft and extending adjacentto the up er side of the topmost annulus.

n testimony whereof I have hereunto af- 'fixed my signature this 13thday of June,

ROBERT MCKNIGHT. Witnesses:

L. M. SIMPSON, D. H. LANG.

TOO

